[0001] The invention relates to a recording arrangement for recording an information signal
in tracks on a record carrier, the recording arrangement comprising
- an input terminal for receiving the information signal,
- channel encoding means for channel encoding the information signal so as to obtain
a channel signal suitable for recording in a track on said record carrier,
the channel signal comprising subsequent signal blocks each signal block comprising
a first block section which comprises a synchronisation signal and a second block
section which comprises a number of channel bytes,
- writing means for writing the channel signal in the track.
[0002] The invention further relates to a record carrier obtained with the recording arrangement,
and to a reproducing arrangement for reproducing the video signal from the record
carrier.
[0003] A recording arrangement as given in the opening paragraph is known from EP-A 492,704,
document (1) in the list of references that can be found at the end of this application.
[0004] The known arrangement is a recording arrangement of the helical scan type and records
an information signal comprising a digital audio signal and a digital video signal
in audio signal recording sectors and video signal recording sectors respectively
in subsequent tracks, where, when recording a track, the video signal recording sector
in a track comes first and is followed by the audio signal recording sector. The order
in which the sectors occur in a track can however also be in the reverse order. Further,
other sectors may be included in a track, such as a clock run-in area located at the
beginning of a track, so as to enable a locking-in of the internal system clock on
the signals read from the track, and preamble and postamble areas that are located
between the various sectors and function as an edit gap. Reference is made in this
respect to the earlier filed European patent applications no.93.202.950, reference
(2) in the list of references and no. 93.201.263, reference (3) in the list of documents.
[0005] The prior art documents relate to proposals for the realisation of a new digital
video cassette (DVC) recorder standard, which enables the recording and reproduction
of digital video and digital audio on/from a longitudinal magnetic record carrier.
This new digital video recorder standard will lead to new digital videorecorders/reproducers
of the so-called DVC type.
[0006] The invention aims at providing a recording arrangement which is capable of recording
other type of information signals in the known tape format as defined in the preamble.
The recording arrangement in accordance with the invention is characterized in that
the recording arrangement is adapted to record an information signal in the form of
an MPEG information signal in accordance with an MPEG format, the MPEG information
signal comprising subsequent transport packets (P
k-j, P
k, P
k+1) having a predetermined fixed length, that the channel encoding means are adapted
to store information included in x transport packets of the MPEG information signal
in the second block sections of a group of y signal blocks of the channel signal,
that the second block sections of the signal blocks comprise a third block section
(TB3.j), and that the channel encoding means are further adapted to generate sequence
number information and store said sequence number information in said third block
section of the second block section, said sequence number information relating to
a sequence number of a signal block in a group of y signal blocks, and that x and
y are integer constants for which holds x≥1 and y>1.
[0007] The invention is based on the following recognition. The draft Grand Alliance HDTV
System Specification dated February 22, 1994, document (4) in the list of references,
more specifically the chapters V and VI of this specification, comprises a description
of a transport system for transmit-ting an MPEG information signal, which includes
a data compressed digital video signal and a corresponding data compressed digital
audio signal, for broad-casting purposes or for transmission via a cable network.
The MPEG information signal is in the form of transport packets having either an equal
length or a variable length in time. In both cases however, a transport packet comprises
188 bytes of information, the first byte being a synchronization byte.
[0008] A transmission of such an MPEG information signal in the form of a recording on and
a reproduction from a record carrier, such as a magnetic record carrier, require special
measures to be taken in order to realize such kind of transmission via the known tape
format. More specifically, the invention relates to storing the transport packets
in the signal blocks of the known tape format.
[0009] Generally, it can be said that, when storing the information included in a number
of x transport packets of the MPEG information signal in a number of y signal blocks,
some unoccupied space remains available in the y signal blocks for the storage of
additional information, which additional information relates to the specific application
of recording and reproducing the MPEG information signal on/from the record carrier.
In a specific example of the DVC format, the second block sections can comprise 77
bytes of information. In that situation, two transport packets, from each of which
the sync byte has been deleted, can be stored in second block sections of five signal
blocks. Now, 11 bytes (= 5 x 77 - 2 x 187) remain available in the five signal blocks.
Those 11 bytes can be divided over the second block sections of the five signal blocks
in various ways so as to obtain the third block sections. One such way is that the
first two bytes of all second block sections are available as third block sections
and that the last byte available can be considered as a third block section to indicate
the boundary between the information of the two transport packets as stored in the
five signal blocks.
[0010] In the above example, identification information identifying the signal block as
being the first signal block of the group of y signal blocks can be stored in a third
block section of the first signal block in a group of y signal blocks. Or, sequence
number information (sequence numbers) relating to the sequence of the signal blocks
can be stored in the third block sections. This sequence number can also be identified
as a continuity counter. The measures proposed result in a number of advantages.
[0011] The advantage of using identification information identifying a signal block as being
the first signal block in a group of y signal blocks, is that the beginning of a group
can be detected, which simplifies the read out of the data during reproduction.
[0012] One advantage using sequence numbers is that, when reproducing the signal blocks,
it can be decided upon retrieval of the sequence numbers, whether a signal block has
been missed because of reproduction errors or not, so that an error correction or
concealment can be carried out. Another advantage is that one may shuffle the information
to be stored in the signal blocks upon recording. Upon retrieval of the sequence numbers
it is possible to realize a corresponding deshuffling in response to the sequence
numbers retrieved so as to obtain the original datastream.
[0013] Further, having sequence numbers included in the third block sections of the signal
blocks, makes it possible to repeat signal blocks in the case that a transport packet
of the MPEG data stream stored in those signal blocks require a higher protection
against errors that can occur during the recording and a subsequent reproduction process.
[0014] The recording arrangement may be further characterized in that the channel encoding
means are adapted to store information included in x transport packets of the MPEG
information signal in the second block sections of a first group of y first signal
blocks of said signal blocks of the channel signal so as to enable a normal play mode
using video information stored in said first group of y first signal blocks during
a normal play reproduction mode, the channel encoding means further being adapted
to retrieve a trick mode video signal from the MPEG information signal and being adapted
to store said trick mode video signal in second block sections of a second group of
z second signal blocks of said signal blocks of the channel signal so as to enable
a trick play mode using the video information stored in said second signal blocks,
that the second block sections of at least one signal block in each first and second
group of first and second signal blocks respectively comprise a third block section
for storing identification information indicating whether the group comprises first
signal blocks or second signal blocks, and that z is an integer such that z>1.
[0015] In a further embodiment, the second block sections of at least those signal blocks
in a group of y signal blocks that comprises the start portion of a transport packet
comprise a third block section for storing sequence number information relating to
a transport packet sequence number corresponding to the transport packet having its
start portion stored in the second block section of the signal block.
[0016] This enables a reproduction in the reproducing arrangement in a normal play mode
using the first signal blocks and a reproduction in a trick play mode using the second
signal blocks, in response to the detection of the information indicating the groups
comprising first signal blocks or second signal blocks respectively.
[0017] The recording arrangement may further be characterized in that the second block sections
of all signal blocks in each first and second group of first and second signal blocks
respectively comprise a third block section for storing identification information
indicating whether the group comprises first signal blocks or second signal blocks.
More specifically, the second block sections of a group of y signal blocks each comprise
a third block section for storing sequence number information relating to a transport
packet sequence number corresponding to the transport packet of which information
is stored in said signal block.
[0018] Storing a packet sequence number has its advantages if an MPEG datastream is received
having a constant bitrate, and comprising a number of different video programs interleaved
in the MPEG datastream. Generally, such datastream has a too high bitrate for recording
the total datastream on the record carrier. The recording arrangement now comprises
a program selector for retrieving one video program and corresponding audio signal
from the MPEG datastream so as to obtain the MPEG information signal for recording.
As information corresponding to only one video program is included in a MPEG transport
packet, such program selector selects only those transport packets from the MPEG datastream
that comprise information corresponding to said only one video program. That means
that some packets of the original MPEG datastream received are deleted. Upon reproduction
however, an MPEG video signal in accordance with the MPEG standard, however now comprising
only the one video program, should be regenerated. Such regenerated datastream should
have the transport packets that were selected upon recording at the same location,
that is in one or other way, dummy packets corresponding to the packets deleted upon
recording must be inserted in the regenerated datastream. Upon recording a sequence
number is added to each transport packet received, that is: also for the packets that
will be deleted. The sequence numbers of the packets that are selected and stored
is stored in the third block section of the signal blocks in which a transport packet
is stored. Upon reproduction, a sequence of numbers is retrieved, where subsequent
numbers will not necessarily be next higher numbers. In that situation one or more
dummy packets must be inserted so as to regenerate the replica of the original MPEG
datastream.
[0019] The recording arrangement can further be characterized in that the recording arrangement
comprises detection means for detecting the moment of receipt of the transport packets
and for generating timing information for each transport packet received, the timing
information for a transport packet corresponding to said moment of receipt of said
transport packet, that the second block sections of at least those signal blocks in
a group of y signal blocks that comprises the start portion of a transport packet
comprise a third block section for storing the timing information for said transport
packet having its start portion stored in the second block section of the signal block.
More specifically, the second block sections of a group of y signal blocks each comprise
a third block section for storing the timing information corresponding to the transport
packet which has information stored in the second block section of said signal block.
[0020] Storing timing information corresponding to transport packet requires that the recording
arrangement is provided with detection means for detecting the time of receipt of
a transport packet. This measure has its advantages if an MPEG datastream is received
having a variable bitrate, and comprising a number of different video programs interleaved
in the MPEG datastream. As has been said above, generally, such datastream has a too
high bitrate for recording the total datastream on the record carrier. The recording
arrangement now comprises a program selector for retrieving one video program with
its corresponding audio signal from the MPEG datastream so as to obtain the MPEG information
signal for recording. As information corresponding to only one video program is included
in a MPEG transport packet, such program selector selects only those transport packets
from the MPEG datastream that comprise information corresponding to said only one
video program. By detecting and storing the timing information corresponding to a
transport packet, the reproducing arrangement will be capable of retrieving the timing
information and recreate the MPEG information signal using said timing information.
[0021] As a result, record carriers will be obtained having signal blocks stored in tracks
on the record carrier, the signal blocks having a first block section which comprises
a synchronisation signal and a second block section which comprises a number of channel
bytes, x transport packets of the MPEG information signal being stored in the second
block sections of a group of y signal blocks of the channel signal. Further in accordance
with the invention,
- the second block section of signal blocks comprise a third block section for storing
sequence number information relating to a sequence number of the signal blocks, and
x and y being integers such that x ≥ 1 and y > 1, or
- the second block sections of the signal blocks each comprise a third block section
for storing identification information indicating whether the signal block comprise
'normal play' data or 'trick mode'data, or
- the second block sections of at least those signal blocks in a group of y signal blocks
that comprises the start portion of a transport packet comprise a third block section
for storing identification information relating to a transport packet sequence number
corresponding to the transport packet having its start portion stored in the second
block section of the signal block, or
- the second block sections of at least those signal blocks in a group of y signal blocks
that comprises the start portion of a transport packet comprise a third block section
for storing the timing information for said transport packet having its start portion
stored in the second block section of the signal block, or
- third block sections comprise information resulting from a combination of one or more
of the measures listed above.
[0022] It will be apparent that a reproducing arrangement will be needed which is adapted
to each specific embodiment of the recording arrangement, so as to enable a reproduction
of the MPEG information signal recorded on the record carrier. Such reproducing arrangement
is the subject of the claims directed to the reproduction arrangement.
[0023] These and other aspects of the invention will be apparent from and elucidated with
reference to the embodiments described hereafter. In the figure description shows
figure 1 the track format of a record carrier of the DVC-type,
figure 2 schematically the contents of the video signal recording sector in the track
of figure 1,
figure 3 schematically the serial MPEG datastream and the format of the transport
packets included in the serial MPEG datastream,
figure 4 an example of the storage of two transport packets in five signal blocks,
figure 5 the contents of the track when having MPEG information recorded in it,
figure 6 an embodiment of the recording arrangement,
figure 7 an embodiment of the reproducing arrangement,
figure 8a an example of an original serial MPEG datastream having a constant bitrate
and packet rate, figure 8b the MPEG datastream that is recorded and figure 8c the
regenerated replica of the original serial MPEG datastream,
figure 9 an embodiment of the 'normal play' processing unit in the recording arrangement
of figure 6,
figure 10 an example of a sequence of three groups of five signal blocks each,
figure 11 another example of a sequence of three groups of five signal blocks each,
figure 12 an example of the 'normal play' processing unit in the reproducing arrangement
of figure 7,
figure 13a an example of an original serial MPEG datastream having a variable bitrate
and packet rate, figure 13b the MPEG datastream that is recorded and figure 13c the
regenerated replica of the original serial MPEG datastream,
figure 14 another embodiment of the 'normal play' processing unit in the recording
arrangement of figure 6,
figure 15 another embodiment of the 'normal play' processing unit in the reproducing
arrangement of figure 7,
figure 16 the record carrier and the read head scanning the record carrier during
a trick play mode,
figure 17 the sequence of signal blocks in a track forming the trick play area.
[0024] Figure 1 shows the format of the signals as they are recorded in a track on a magnetic
record carrier by means of a helical scan videorecorder of the DVC type. The left
end of the track 1 in figure 1 is the start of the track and the right end of the
track is the terminal part of the track. The track comprises a number of track parts.
The track part denoted by G1 is the pre-amble track part. An example of the preamble
track part G1 has been described extensively in reference (1).
[0025] The track part G1 is followed by tracking tone recording part TP1, which is denoted
by ITI (insert timing information) track part and which contains a tracking tone,
synchronisation information and identification (or timing) information. Further explanation
of the contents of the ITI track can be found in reference (3).
[0026] The track part TP1 is followed by an edit gap G2. The edit gap G2 is followed by
the track part TP2, which is the audio signal recording sector and comprises digital
audio information. The edit gap G3 is followed by a track part TP3 which is the video
signal recording sector and comprises digital video information. The edit gap G4 is
followed by a track part TP4, denoted by INDEX and which comprises amongst others
subcode information, such as absolute and/or relative time information and a table
of contents (TOC). The track is terminated by the track part G5. It can be said that
the sequence order in which the parts TP1, TP2 and TP3 occur in the tracks may be
different.
[0027] The contents of the video signal recording sector TP3 is given in figure 2. Figure
2 in fact shows schematically a number of 149 horizontal lines, denoted by j=1 to
j=149, having bytes of information stored in it. The 149 lines are in fact 149 signal
blocks (or sync blocks) that are stored sequentially in the video signal recording
sector TP3. 90 bytes of information, denoted by i=1 to i=90, are stored in each signal
block.
[0028] The first two bytes (i=1 and i=2) of each signal block form a synchronisation pattern
of 2 bytes long. The following three bytes in each signal block form an ID code, comprising
amongst others information which indicates the sequence number of the signal block
in the video signal recording part TP3. The last eight bytes in the signal blocks
form horizontal parity information. Vertical parity information is stored in the storage
locations i=6 to i=82 inclusive of the last 11 signal blocks.
[0029] Bytes of video signal information are stored in the storage locations i=6 to i=82
inclusive of the signal blocks having the sequence numbers j =3 to j =137 inclusive.
Bytes of auxiliary data are stored in the storage locations i=6 to i=82 inclusive
of the signal blocks having the sequence numbers j = 1, 2 and 138. The signal blocks
are stored sequentially in the video signal part TP3, starting with the signal block
denoted y=1, followed by the signal block denoted j=2, and so on until the signal
block denoted j=149.
[0030] The auxiliary data for storage in the signal blocks denoted j = 1, 2 and 138 can
be teletext data or control data.
[0031] It should be noted here that it can be specified that the auxiliary data will be
stored in a different location in the memory. Reference is made in this respect to
document (1), figure 13, where the auxiliary data is stored in the memory part denoted
by III.
[0032] Figure 3 shows schematically the MPEG datastream applied to a recording arrangement
in accordance with the invention. The MPEG datastream comprises subsequent transport
packets, denoted by ..., P
k-1, P
k, P
k+1, ... The packets each comprise a packet header portion PH of 4 bytes long and a body
portion of 184 bytes long. The transport packets can be transmitted in a datastream
having a constant bitrate. This means that the packets are equally long, viewed in
time, and are received at a fixed packet rate. The transport packets may also be transmitted
in a datastream having a variable bitrate. In this situation, the packets need not
be of the same length, viewed in time, and may be received with a variable packet
rate. The first byte in the packet header PH is a sync byte. The sync byte is identical
for all the transport packets. The other three bytes in the header comprise ID information,
such as a packet identifier. For a further explanation of the contents of the ID information,
reference is made to document (4) in the list of references, more specifically chapter
V, paragraph 5.1 on page 27.
[0033] The body portion of the transport packets comprise each 184 bytes for storing the
video and audio information that should be transmitted in accordance with the MPEG
format. The body portion of one transport packet can store either audio information
corresponding to a certain video signal, or the video signal. Further, in the case
that a number of video programs are transmitted via the MPEG datastream, the body
portion stores a video signal corresponding to one of such video programs transmitted.
[0034] The invention now aims at recording the video signal, and the corresponding audio
signal as may be appreciated, corresponding to one of those video programs transmitted
via the MPEG data stream on the record carrier having the track format disclosed in
figure 1 and 2. Information stored in the transport packets should be stored in the
signal blocks, more specifically, in the 135 signal blocks denoted j=3 to j=137 in
the video signal recording part TP3 of a track. The two sync bytes, denoted i=1 and
2, the ID information in the form of the three ID bytes denoted i=3, 4 and 5, as well
as the 8 horizontal parity bytes, denoted by i=83 to 90, in those signal blocks are
required for a correct recording and reproduction. As a consequence, only the 77 bytes,
denoted by i=6 to 82, in the signal blocks denoted by j=3 to 137, are available for
the storage of the transport packets of the MPEG information. The part of the signal
blocks formed by the 77 bytes i=6 to 82 is defined as being the second block sections
of the signal blocks.
[0035] As synchronization during recording and reproduction is assured by means of the sync
words in each of the signal blocks, there is no need for transmitting the sync bytes
of the transport packets via the record carrier. So, before storing the information
comprised in the transport packets in the second block sections of the signal blocks
denoted by j = 3 to 135, the sync byte of all the transport packets is thrown away.
As a result only 187 bytes of information should be stored in the signal blocks for
each transport packet.
[0036] A simple calculation makes clear that two transport packets can be stored in five
signal blocks, and that 11 bytes remain available for the storage of other information.
Figure 4 gives an example of how the two transport packets can be stored in the second
block sections of the group of five signal blocks, denoted SB1 to SB5 in figure 4.
Figure 4 only shows the contents of the second block sections of length of 77 bytes
included in the signal blocks. As can be seen in figure 4, the 11 bytes are divided
over the group of five signal blocks such that each second block section comprises
a third block section TB3.1 to TB3.5, of two bytes long at the beginning of the second
block sections of the five signal blocks SB1 to SB5 respectively, and a third block
section in the form of one byte, denoted by FB, is available in the third signal block
SB3. The 187 bytes of the first transport packet are stored in the signal blocks SB1,
SB2 and SB3, where the three ID bytes of the packet header of the first transport
packet, indicated by TH1, are stored first in the signal block SB1, directly after
the third block section TB3.1, and next the first 72 first bytes in the body of the
first transport packet are stored thereafter in the second block section of the signal
block SB1. The next 75 bytes in the body of the first transport packet are stored
in the second block section of the signal block SB2, after the third block section
TB3.2, and the last 37 bytes in the body of the first transport packet are stored
in the second block section of the signal block SB3, after the third block section
TB3.3.
[0037] Next comes the byte FB, which indicates the boundary between the information of the
first and second transport packets stored in the group of five signal blocks. The
187 bytes of the second transport packet are stored in the signal blocks SB3, SB4
and SB5, where the three ID bytes of the packet header of the second transport packet,
indicated by TH2, are stored first in the signal block SB3, directly after the byte
FB. Next the first 34 first bytes in the body of the second transport packet are stored
thereafter in the second block section of the signal block SB3. The next 75 bytes
in the body of the second transport packet are stored in the second block section
of the signal block SB4, after the third block section TB3.4, and the last 75 bytes
in the body of the second transport packet are stored in the second block section
of the signal block SB5, after the third block section TB3.5.
[0038] It should be noted that also another spreading of the 11 available bytes over the
five signal blocks is possible. As an example, the 11 bytes could have been split
into two third block sections, the one third block section having as an example 6
bytes and being located at the beginning of the first signal block SB1, and the other
third block section of 5 bytes long being located in the third signal block and indicating
the boundary between the two transport packets stored in the five signal blocks. Another
example could have been to have a third block section located at the beginning of
the signal blocks SB1 and SB3 and another third block section in the third signal
block SB3, indicating the boundary between the two transport packets stored in the
five signal blocks, where the third block section in the signal block SB1 can have
eg. 4 bytes, the first third block section in the signal block SB3 eg. 3 bytes and
the third block section in signal block SB3 indicating the said boundary being eg.
4 bytes long.
[0039] The third block sections TB3.1 to TB3.5 can be used for the storage of additional
information. As a first example, the third block section TB3.1 can include an indication
identifying the signal block SB1 as being the first signal block in a group of five
signal blocks. This can be realized by storing in one specific bit location in the
third block section TB3.1 a bit value of a certain polarity, such as '0' or '1'. In
the same bit locations in the third block sections TB3.2 to TB3.5 a bit value of the
opposite polarity should be stored. In another example, sequence number information,
eg. sequence numbers running from 1 to 5 can be stored in the third block sections
TB3.1 to TB5 respectively, of the group of five signal blocks, where the third block
section TB3.1 has the sequence number '1' and the third block section TB3.5 has the
sequence number '5' stored in them. Three specific bit locations in the third block
sections TB3.1 to TB3.5 are required to stored the sequence numbers. The sequence
numbers can however also run across the group boundaries so as to identify a larger
sequence of signal blocks, eg within one track, or even in more than one track.
[0040] In another example, one specific bit location in the third block sections TB3.1 to
TB3.5 of a group of five signal blocks can be used to store either a bit value of
one polarity, such as '0' or '1', so as to indicate that the video data included in
the signal block is so-called 'normal play' data, or a bit value of the opposite polarity,
so as to indicate that the video data included in the signal block is so-called 'trick
play' video data. The use of the 'normal play' video data and 'trick play' video data
will be explained later.
[0041] In again another example, sequence numbers are generated in response to transport
packets in the MPEG datastream that is received. As has been explained earlier, such
MPEG datastream can include more than one video programs. As the bitrate of the MPEG
datastream is normally higher than the bitrate of the signal that can be recorded,
only one video program may be selected from the serial MPEG datastream for recording.
Selection of one video program means selection of transport packets out of the datastream
of the MPEG datastream that comprise the information relating to said video program,
and deleting the other packets. Consequently the serial array of transport packets
that will be recorded have sequence numbers that not necessarily are next higher numbers,
as those sequence numbers of the transport packets deleted are not present. When storing
the sequence numbers in the third block sections, those sequence numbers can be retrieved
upon reproduction. By checking the subsequent sequence numbers retrieved, it can be
established whether the original MPEG datastream applied to the recording arrangement,
originally included deleted transport packets between two transport packets reproduced.
If so, a replica of the original MPEG datastream can be regenerated by inserting one
or more dummy packets between the two transport packets reproduced.
[0042] In a related example, timing information is stored in the third block sections, for
the same reason as given above, namely for regenerating a replica of the original
MPEG datastream, in the case that such datastream is a datastream having a variable
bitrate.
[0043] It will be clear that also a combination of the additional information described
above can be included in the 11 bytes available for the storage of such information
in a group of five signal blocks.
[0044] As an example, it has been made clear above that a 3-bit word is needed in the third
block sections to indicate the sequence numbers of the signal blocks in the group
of five signal blocks. More specifically, the 3-bit words '000', '001', '010', '011'
and '100' could have been used to identify the sequence. That means that the 3-bit
words '101', '110' and '111' remain available for a further identification. As an
example, the 3-bit words '101' and '110' could be used to identify either 'normal
play' data or 'trick mode' data.
[0045] Figure 5 shows the track format of the track if the MPEG information has been stored
in the second block portions of the signal blocks of the track portion TP3 of figure
1, now denoted by track portion TP3'. Figure 5 shows the first two signal blocks (j=1,2)
in the track portion TP3' that still includes the auxiliary data, followed by 135
signal blocks (j=3 to j = 137) now comprising the MPEG information and the additional
information described above. Next one signal block (j=138) also comprising the auxiliary
data, followed by 11 signal blocks comprising the parity information. The storage
of the MPEG information and the additional information in the 135 signal blocks may
require an additional error encoding step to be carried out on the said information,
resulting in additional parity information that should also be stored in a track.
As the MPEG information, which includes video information and corresponding audio
information, is stored in the signal 135 blocks in the track portion TP3', there is
no need for storing audio information in the track portion TP2 of figure 1. This portion,
now denoted by TP2' in figure 5, can be used to store the parity information resulting
from the additional error encoding step.
[0046] Figure 6 shows schematically an embodiment of the recording arrangement. The recording
arrangement comprises an input terminal 11 for receiving the MPEG serial datastream
for recording transport packets included in the datastream in the signal blocks of
the track portions TP3' of the tracks. The input terminal 11 is coupled to an input
12 of a 'normal play' processing unit 14. Optionally, a 'trick play' processing unit
16 is provided having an input 17 also coupled to the input terminal 11. Outputs 19
and 20 of the 'normal play' processing unit 14 and the 'trick play' processing unit
16 (if present) are coupled to corresponding inputs of a multiplexer 22. It will be
clear that in the absence of the 'trick play' processing unit 16, also the multiplexer
22 will be absent.
[0047] An auxiliary signal generator 24 is present for supplying the auxiliary signal information
for storage in the signal blocks denoted by j=1,2 and 138, see figure 2. Outputs of
the multiplexer 22 and the generator 24 are coupled to corresponding inputs of an
error correction encoder unit 26. The error correction encoder unit 26 is capable
of carrying out a first error correction encoding step, denoted ECC3 and a second
error correction encoding step, denoted ECC2. Next a third error correction encoding
step, denoted ECC1, is carried out in an error correction encoder unit 28.
[0048] The recording arrangement further comprises a generator 30 for adding the ID information
in the bytes i=3, 4 and 5 of the signal blocks, see figure 2, for adding the index
information for storage in the track portion TP4, see figure 5, and the gap information
for realizing the gaps G1 to G5, see figure 5. After combination of the signals in
the combining unit 32, the combined signal is applied to a unit 34, in which an encoding
is carried out where each time 24-bit words of the incoming bitstream are converted
into 25-bit words, where a sync word is added so as to obtain the first two bytes
(i=1,2) in the signal blocks and where the ITI information is added for storage in
the track portion TP1.
[0049] The 24-to-25 encoding carried out in the encoding unit 34 is well known in the art.
Reference is made in this respect to US patent spec. no. 5,142,421, document (5) in
the list of references. This document also a way of adding the sync word to the datastream.
[0050] An output of the encoding unit 34 is coupled to an input of a writing unit 36, in
which the datastream obtained with the encoding unit 34 is recorded in the slant tracks
on the record carrier, by means of at least one write head 42.
[0051] The first error correction encoding step, denoted ECC3, is required so as to realize
the additional error protection of the MPEG information to be recorded on the record
carrier, and results in parity information that will be stored in the track portion
TP2' , as has been explained previously. The second error correction encoding step,
denoted ECC2, results in the vertical parity information that will be stored in the
11 signal blocks (j=139 to 149) of the track portion TP3', see the figures 2 and 5.
The third error correction encoding step, denoted ECC1, results in the horizontal
parity information that will be stored in the last 8 bytes of the signal blocks in
the track portion TP3', see the figure 2 and 5.
[0052] Before a further description of the 'normal play' processing unit 14 and the 'trick
play' processing unit 16 of the recording arrangement of figure 6 will be given, first
a schematic description of the reproducing arrangement will be given. This has the
advantage that, when further describing certain measures applied in the processing
units 14 and 16, a direct relation can be given to the advantages and consequences
of those measures during reproduction.
[0053] Figure 7 shows schematically an embodiment of a reproduction arrangement for reproducing
information from the record carrier 40 obtained with the recording arrangement of
figure 6. The reproduction arrangement comprises a reading unit 50, having at least
one reading head 52 for reading information from the slant tracks on the record carrier
40. An output of the reading unit 50 is coupled to an input of a decoding unit 54,
which carries out a 25-to-24 decoding on the signal read out, so as to convert 25-bit
words in the incoming datastream into 24-bit words. Next, after having selected out
in the selector unit 56 all those information that is not required for recreating
a replica of the original MPEG datastream, an error correction is carried out in the
error correction unit 58. It will be clear that the error correction carried out has
three steps. One error correction step based on the ECC1, using the horizontal parities,
see figure 2, a second error correction step based on ECC2, using the vertical parities,
and a third error correction step based on ECC3, using the parity information stored
in the track portion TP2' , see figure 5.
[0054] The output terminal of the error correction unit 58 is coupled to an input of a 'normal
play' processing unit 60. Optionally, a 'trick play' processing unit 62 is provided
having an input also coupled to the output of the error correction unit 58. Outputs
64 and 65 of the 'normal play' processing unit 60 and the 'trick play' processing
unit 62 (if present) are coupled to corresponding terminals a and b respectively of
a switch 66, a c-terminal of which is coupled to an output terminal 68. It will be
clear that in the absence of the 'trick play' processing unit 62, also the switch
66 will be absent. If the reproducing arrangement is switched into a 'normal play'
reproduction mode, this means that the record carrier is transported at a nominal
speed, that the 'normal play' processing unit 60 is enabled and the switch 66 is switched
into the position a-c. If the reproducing arrangement is switched into a 'trick play'
reproduction mode, also called 'feature mode', this means that the record carrier
is transported at a speed other than the nominal speed, that the 'trick play' processing
unit 62 is enabled and the switch 66 is switched into the position b-c.
[0055] Now a further discussion will be given of the processing units 14 and 16 of figure
6, in combination with the processing units 60 and 62 of figure 7.
[0056] It is assumed that the recording arrangement is capable of selecting one video program
and its corresponding audio signal from the serial MPEG datastream that is applied
to the input terminal 11, in response to a selection signal supplied to the arrangement
by a user. As has been said earlier, only those transport packets in the serial MPEG
stream should be selected that include information relating to the video program selected.
Figure 8a shows the serial MPEG datastream as a function of time comprising the transport
packets denoted P
k. It should be noted that the transport packets of the MPEG datastream do not comprise
a packet number. The packet number k, given to the packets in figure 8a are therefore
the numbers that will be generated by the packet number generator 86 of figure 9 that
will be discussed later.
[0057] Selecting only those packets of the packets P
k of figure 8a that include information relating to the video program selected means,
as an example, that the packets P
k-4, P
k-1, P
k, P
k+2, P
k+4, P
k+8 will be selected and that the intermediate packets will be thrown away. As a result,
a datastream has been obtained in the recording arrangement for recording on the record
carrier, as shown in figure 8b, which shows the datastream as a function of time.
No conclusion should be drawn from the timing in the time scales of figure 8a and
8b, nor from the relative location between the time scales in figure 8a and 8b. This
for the reason that, as has been said previously, the bitrate of the original MPEG
datastream (figure 8a) is different from (higher than) the bitrate with which the
selected transport packets will be recorded on the record carrier.
[0058] An embodiment of the 'normal play' processing unit 14 for recording a datastream
as shown in figure 8b is shown schematically in figure 9. The embodiment denoted 14'
in figure 9, comprise a selector unit 76 having an input coupled to the input 11 of
the unit 14'. The selector unit 76 has another input 78 for receiving the selection
signal supplied by the user. An output 79 of the selector unit 78 is coupled to the
input of a sync stripper 80, whose output is coupled to a signal combining unit 82.
Further, an output 81 of the selector 76 is coupled to a control input 83 of the combining
unit 82, for supplying a control signal to the combining unit 82.
[0059] The input 11 is further coupled to an input of a packet detector 84, which has an
output coupled to an input of a packet number generator 86. An output of the generator
86 is coupled to a second input of the combining unit 82.
[0060] The selector 76 selects the transport packets P
k-4, P
k-1, P
k, P
k+2, P
k+4, P
k+8 from the serial MPEG datastream applied to the input 11 in response to the selection
signal received via the input 78. The packets selected are applied to the sync stripper
80, in which the first sync byte in the packet header PH, see figure 3, is deleted
from the packets, in accordance with a description given previously. The packet detector
84 detects the receipt of each packet in the original serial MPEG data stream applied
to the input 11 and generates a clock impulse for each packet detected. The generator
86 includes a counter that counts up under the influence of the clock impulses applied
to the generator 86. As a consequence a next higher count number is applied to the
output for each clock impulse received. At the output 87 of the generator 86 thus
appear count numbers .... k-4, k-3, k-2, k-1, k, k+1, k+2, k+3, k+8, ... Under the
influence of the control signal applied to the control input 83 of the combining unit
82, the control unit combines the packets P
k-4, P
k-1, P
k, P
k+2, P
k+4, P
k+8 selected by the selector 76 as well as the count numbers k-4, k-1, k, k+2, k+4, k+8
out of the count number stream supplied by the packet number generator 86 for storage
into the signal blocks.
[0061] Figure 10 shows an example how the transport packets and the corresponding packet
numbers can be stored in the groups of five signal blocks. Figure 10 shows three subsequent
groups of five signal blocks, denoted G1, G2 and G3 in which the information is stored.
In the third block section TB3.1 of the first signal block SB1 of the group G1, the
packet number k-4 is stored and the information comprised in the packet P
k-4 is stored thereafter in the signal blocks SB1, SB2 and SB3 of the group G1. In the
third block section denoted FB of the third signal block SB3 of the group G1, the
packet number k-1 is stored and the information comprised in the packet P
k-1 is stored thereafter in the signal blocks SB3, SB4 and SB5 of the group G1. In the
third block section TB3.1 of the first signal block SB1 of the group G2, the packet
number k is stored and the information comprised in the packet P
k is stored thereafter in the signal blocks SB1, SB2 and SB3 of the group G2. In the
third block section denoted FB of the third signal block SB3 of the group G2, the
packet number k+2 is stored and the information comprised in the packet P
k+2 is stored thereafter in the signal blocks SB3, SB4 and SB5 of the group G2. In the
third block section TB3.1 of the first signal block SB1 of the group G3, the packet
number k+4 is stored and the information comprised in the packet P
k+4 is stored thereafter in the signal blocks SB1, SB2 and SB3 of the group G3. In the
third block section denoted FB of the third signal block SB3 of the group G3, the
packet number k+8 is stored and the information comprised in the packet P
k+8 is stored thereafter in the signal blocks SB3, SB4 and SB5 of the group G3. As long
as the number of bits of the packet number is smaller than or equal to 8, the packet
number will fit in the third block section FB, which is 1 byte long.
[0062] Another example of storing the packet numbers in the third block sections is given
in figure 11. In the third block sections TB3.1, TB3.2 and TB3.3 of the signal blocks
SB1, SB2 and SB3 respectively of the group G1, the packet number k-4 is stored and
the information comprised in the packet P
k-4 is stored in the signal blocks SB1, SB2 and SB3 of the group G1, as explained previously
with reference to figure 4. In the third block section denoted FB of the third signal
block SB3 of the group G1, as well as in the third block sections TB3.4 and TB3.5
of the signal blocks SB4 and SB5 of the group G1, the packet number k-1 is stored
and the information comprised in the packet P
k-1 is stored in the signal blocks SB3, SB4 and SB5 of the group G1, as explained previously
with reference to figure 4. In the third block sections TB3.1, TB3.2 and TB3.3 of
the signal blocks SB1, SB2 and SB3 respectively of the group G2, the packet number
k is stored and the information comprised in the packet P
k is stored in the signal blocks SB1, SB2 and SB3 of the group G2. In the third block
section denoted FB of the third signal block SB3 of the group G2, as well as in the
third block sections TB3.4 and TB3.5 of the signal blocks SB4 and SB5 respectively
of the group G2, the packet number k+2 is stored and the information comprised in
the packet P
k+2 is stored in the signal blocks SB3, SB4 and SB5 of the group G2. In the third block
sections TB3.1, TB3.2 and TB3.3 of the signal blocks SB1, SB2 and SB3 of the group
G3, the packet number k+4 is stored and the information comprised in the packet P
k+4 is stored in the signal blocks SB1, SB2 and SB3 of the group G3. In the third block
section denoted FB of the third signal block SB3 of the group G3, as well as in the
third block sections TB3.4 and TB3.5 of the signal blocks SB4 and SB5 of the group
G3, the packet number k+8 is stored and the information comprised in the packet P
k+8 is stored in the signal blocks SB3, SB4 and SB5 of the group G3.
[0063] Instead of storing the packet number k-4 in the third block section TB3.3 of the
signal block SB3 in group G1, one could have stored the packet number k-1 in said
third block section. Instead of storing the packet number k in the third block section
TB3.3 of the signal block SB3 in group G2, one could have stored the packet number
k+2 in said third block section. Instead of storing the packet number k+4 in the third
block section TB3.3 of the signal block SB3 in group G3, one could have stored the
packet number k+8 in said third block section.
[0064] Figure 12 schematically shows an embodiment of the 'normal play' processing unit
60 of the reproducing arrangement of figure 7, for regenerating a replica of the original
MPEG datastream of figure 8a from the datastream as shown in figure 8b, using the
packet number information also stored in the signal blocks, in the way described above.
The regenerated replica of the MPEG datastream is shown in figure 8c. The embodiment
of the 'normal play' processing unit of figure 12, denoted by 60', comprises a demultiplexer
90 having its input coupled to the input 59 of the processing unit 60' for receiving
the subsequent groups of signal blocks, such as the groups G1, G2 and G3 of figure
10 or 11, and for retrieving therefrom the packets that are supplied to an output
91 and for retrieving the array of packet numbers ... k-4, k-1, k, k+2, k+4, k+8 ....
from the third block sections in the signal blocks, and for supplying the said array
of packet numbers to an output 92. The packets retrieved are supplied to a sync adder
circuit 94 in which the one byte long packet sync signal is reinserted as first byte
in all the packets. The packets thus obtained are supplied to an input 95 of a combining
unit 96. The output 92 of the demultiplexer 90 is coupled to inputs 97 and 98 of the
combining unit 96 and a dummy packet generator 100 respectively. An output 102 of
the dummy packet generator 100 is coupled to an input 103 of the combining unit 103.
An output 105 of the combining unit 96 is coupled to the output 64 of the 'normal
play' processing unit 60'.
[0065] Let us now assume that the packet P
k-4 and the packet number k-4 are retrieved from the first group G1 of five signal blocks,
and are applied to the combining unit 96 and the dummy packet generator 100. This
results in the packet P
k-4 being supplied to the output 105 by the combining unit 96. Next, the packet P
k-1 and the packet number k-1 are retrieved from the group G1 and are applied to the
combining unit 96 and the dummy packet generator 100. It is established, by means
of a comparator and/or a subtractor (not shown), that the packet number k-1 is not
the next higher packet number of the packet number k-4, received previously and that
two packet numbers are missing. As a result, the dummy packet generator 100 generates
twice a dummy packet of the same length as the other packets in the datastream, and
the combining unit 96 inserts those two dummy packets in the serial datastream, directly
after the packet P
k-4, see figure 8c. Next, the combining unit 96 inserts the packet P
k-1 into the serial datastream.
[0066] It should be noted here, that there is no specific need for the generator 100 to
be explicitly a dummy packet generator. It is also possible that the generator 100
is a dummy info generator that generates dummy info of a certain length in time, this
length of time being equal to the length of time of a packet or equal to a multiple
of the length of time of a packet.
[0067] The packet P
k is the next packet that is retrieved by the demultiplexer 90, and the packet is supplied,
after the addition of the sync byte, to the input 95 of the combining unit 96. The
packet number k is supplied to the inputs 97 and 98 of the combining unit 96 and the
dummy packet generator 100. As the packet number k is the next higher packet number
to packet number k-1, no dummy packet is generated, and the packet P
k is supplied to the output 105.
[0068] Next the packet P
k+2 is retrieved. After comparison of the packet number k+2 with the previous packet
number k retrieved, it appears that one dummy packet must be inserted in the serial
datastream. Next, the packet P
k+2 is added to the datastream, see figure 8c. This process is continued for the other
packets, so as to obtain the regenerated replica of the MPEG datastream of figure
8c. When comparing figure 8a and 8c, it will be clear that figure 8c shows an MPEG
serial datastream having the same bitrate and packet rate as the MPEG datastream of
figure 8a. This datastream can now be applied to a standard MPEG decoder which is
capable of decoding the one video program selected by the recording arrangement during
recording, from the MPEG datastream of figure 8c.
[0069] Figure 13a shows an MPEG serial datastream as a function of time, the datastream
comprising packets P
k having a variable length, and the bitrate in the datastream also being variable.
It should be noted that the transport packets of the MPEG datastream do not comprise
a packet number. The packet number k, given to the packets in figure 13a are therefore
only added in this description for identification purposes. Figure 14 shows schematically
an embodiment of the 'normal play' processing unit 14 for recording one video program
that is included in the serial datastream as shown in figure 13a. The embodiment denoted
14" in figure 14 shows large resemblances with the embodiment of figure 9. The embodiment
14" differs from the embodiment of figure 9, in that, instead of the packet number
generator 86, now a timing detector 110 is present, having its input coupled to the
output of the detector 84, and having its output 111 coupled to the input 112 of the
combining unit 82.
[0070] Selecting only those packets of the packets P
k in the serial datastream of figure 13a that include information relating to one video
program that will be selected again means, as an example, that the packets P
k-4, P
k-1, P
k, P
k+2, P
k+4, P
k+8 will be selected and that the intermediate packets will be thrown away. Figure 13b
shows the datastream of the selected packets that will be stored in the groups of
signal blocks, as already has been explained with reference to the figures 10 and
11. It should be noted also here, that there is no time relationship between the time
axes in the figures 13a and 13b. Further, it should be noted that, although the packets
in the datastream of figure 13a have unequal length, they all include 188 bytes of
information. Therefore, the packets selected and displayed in figure 13b have been
shown as packets having an equal length.
[0071] The embodiment of figure 14 receives the datastream of figure 13a and selects therefrom
the packets P
k-4, P
k-1, P
k, P
k+2, P
k+4, P
k+8. The packet detector 84 detects the receipt of each packet in the original serial
MPEG data stream applied to the input 11 and generates a clock impulse for each packet
detected. In response to each clock impulse received, the timing detector 110 detects
the time instants t
k, see figure 13a, of occurrence of the packets P
k. Thus at the output 111 of the detector 110 appear the time instants ... t
k-4, t
k-3, t
k-2, t
k-1, t
k, ... etc. Moreover the time detector 110 detects the lengths of the time intervals
dt
k between two subsequent time instants, where dt
k equals the time interval t
k+1-t
k. Those time interval values dt
k are also applied to the output 111. Under the influence of the control signal applied
to the control input 83 of the combining unit 82', the control unit combines the packets
P
k-4, P
k-1, P
k, P
k+2, P
k+4, P
k+8 selected by the selector 76 as well as the time instants and corresponding time intervals
t
k-4, dt
k-4, t
k-1, dt
k-1, t
k, dt
k, t
k+2, dt
k+2, t
k+4, dt
k+4, t
k+8, dt
k+8 out of the information stream supplied by the timing detector 110 for storage into
the signal blocks.
[0072] The storage of the transport packets in the signal blocks will be carried out in
the same way as discussed above with reference to the figures 10 and 11. The storage
of the timing information in the third block sections can be as follows.
[0073] In the third block section TB3.1 of the first signal block SB1 of the group G1 of
figure 10, the timing information t
k-4 and dt
k-4 is stored. In the third block section denoted FB of the third signal block SB3 of
the group G1, the timing information t
k-1 and dt
k-1 is stored. In the third block section TB3.1 of the first signal block SB1 of the
group G2, the timing information t
k and dt
k is stored. In the third block section denoted FB of the third signal block SB3 of
the group G2, the timing information t
k+2 and dt
k+2 is stored. In the third block section TB3.1 of the first signal block SB1 of the
group G3, the timing information t
k+4 and dt
k+4 is stored. In the third block section denoted FB of the third signal block SB3 of
the group G3, the timing information t
k+8 and dt
k+8 is stored.
[0074] It may be so that the third block section TB3.1 in the first signal block SB1 in
the groups and/or the third block section FB in the third signal block SB3 in the
groups is/are too small for storing the timing information. In that case, the timing
information can be stored somewhere else, or can be stored partly in the third block
section TB3.1 and FB and partly somewhere else, see below.
[0075] In accordance with the example of figure 11, the timing information t
k-4 and dt
k-4 is stored in the third block sections TB3.1, TB3.2 and TB3.3 of the signal blocks
SB1, SB2 and SB3 respectively of the group G1. The storage of the timing information
can be carried out once in the total storage capacity of the third block sections
TB3.1, TB3.2 and TB3.3 or can be repeated at least once. As an example, the timing
information t
k-4 and dt
k-4 is stored in each of the third block sections TB3.1, TB3.2 and TB3.3. The timing
information t
k-1, and dt
k-1 can be stored in the third block sections FB, TB3.4, and TB3.5 of the signal blocks
SB3, SB4 and SB5 respectively of the group G1. The storage of the timing information
can be carried out once in the total storage capacity of the third block sections
FB, TB3.4 and TB3.5 or can be repeated at least once. As an example, the timing information
t
k-4 and dt
k-4 is stored in each of the third block sections TB3.4 and TB3.5. It may be possible
to store the timing information for the packet P
k-1 in the third block section TB3.3. It is further possible to store the timing information
in the third block sections TB3.4 and TB3.5, and not in the block section FB.
[0076] The timing information for the packet P
k can be stored in the third block sections of the group G2 in the same way as the
timing information for the packet P
k-4 has been stored in the third block sections of the group G1. The timing information
for the packet P
k+2 can be stored in the third block sections of the group G2 in the same way as the
timing information for the packet P
k-1 has been stored in the third block sections of the group G1.
[0077] The timing information for the packet P
+4k can be stored in the third block sections of the group G3 in the same way as the
timing information for the packet P
k-4 has been stored in the third block sections of the group G1. The timing information
for the packet P
k+8 can be stored in the third block sections of the group G3 in the same way as the
timing information for the packet P
k-1 has been stored in the third block sections of the group G1.
[0078] Figure 15 schematically shows an embodiment of the 'normal play' processing unit
60 of the reproducing arrangement of figure 7, denoted 60", for regenerating a replica
of the original MPEG datastream of figure 13a from the datastream as shown in figure
13b, using the timing information also stored in the signal blocks, in the way described
above. The regenerated replica of the MPEG datastream is shown in figure 13c. The
embodiment 60"of figure 12 shows a large resemblance with the processing unit of figure
12. The demultiplexer 90' is again adapted to retrieve the packets from the subsequent
groups of signal blocks, and to supply the packets to the output 91. The demultiplexer
90' is further adapted to retrieving the timing information t
k and dt
k from the third block sections in the signal blocks, and for supplying the said timing
information to the output 92. A sync byte is added to each packet in the sync adder
94. The packets thus obtained are supplied to the input 95 of the combining unit 96'.
The output 92 of the demultiplexer 90 is coupled to inputs 97 and 98 of the combining
unit 96' and a dummy info generator 100' respectively for supplying the timing information
to the combining unit 96' and the generator 100'.
[0079] Let us now assume that the packet P
k-4 and the corresponding timing information are retrieved from the first group G1 of
five signal blocks, and are applied to the combining unit 96' and the dummy packet
generator 100'. This results in the packet P
k-4 being supplied to the output 105 by the combining unit 96', in response to the timing
information. The length of the packet P
k-4 will be equal to dt
k-4, and the packet will be applied to the output 105 at a time instant corresponding
to t
k-4. Next, the packet P
k-1 and the timing information corresponding to the packet P
k-1 are retrieved from the group G1 and are applied to the combining unit 96' and the
dummy packet generator 100'. It is established, by means of a comparator and/or a
subtractor (not shown), that the time instant t
k-1 is not equal to t
k-4+dt
k-4. Consequently at least one packet following the packet P
k-4 has been thrown away during recording. As a result, the dummy info generator 100'
generates a block of dummy information so as to fill the gap between the end of the
packet P
k-4, at the time instant t
k-4+dt
k-4, and the time instant t
k-1, see figure 13c.
[0080] Next, the combining unit 96' inserts the packet P
k-1 having the length dt
k-1 into the serial datastream.
[0081] The packet P
k is the next packet that is retrieved by the demultiplexer 90, and the packet is supplied,
after the addition of the sync byte, to the input 95 of the combining unit 96'. The
timing information corresponding to the packet P
k is supplied to the inputs 97 and 98 of the combining unit 96 and the dummy info generator
100'. As t
k equals t
k-1+dt
k-1, no dummy information need to be is generated, and the packet P
k is supplied to the output 105.
[0082] Next the packet P
k+2 is retrieved. After comparison of t
k+2 with t
k+dt
k, it is established that a gap is present that need to be filled with dummy information
generated by the generator 100'. Next, the packet P
k+2 having a length dt
k+2 is added to the datastream, see figure 13c. This process is continued for the other
packets, so as to obtain the regenerated replica of the MPEG datastream of figure
13c. When comparing figure 13a and 13c, it will be clear that figure 13c shows an
MPEG serial datastream having the same (variable) bitrate and packet rate as the MPEG
datastream of figure 13a. This datastream can now be applied to a standard MPEG decoder
which is capable of decoding the one video program selected by the recording arrangement
during recording, from the MPEG datastream of figure 13c having the variable bitrate
and packet rate.
[0083] Now, other information will be described that can be inserted in the free space in
the groups of signal blocks alone or together with the packet number information and
or the timing information described above.
[0084] One example of such other information is the information identifying a signal block
in a group of y(=5) signal blocks to be the first signal block in the group of signal
blocks. Such information can be stored in the third block sections TB3.1 of the signal
blocks SB1 in the groups G1, G2 and G3, in the figures 10 and 11.
[0085] Another example of such other information is the inclusion of a signal block number
in the third block sections of the signal blocks, such as in the situation of figure
11. Signal block numbering can be carried out within a group, so that in the example
of figure 11, the numbers 1 to 5 are stored in the third block sections TB3.1 to TB3.5
respectively of the signal blocks SB1 to SB5 in each group. Signal block numbering
can also be realized for a larger number of signal blocks, belonging to more than
one group of signal blocks. One could imagine that all the signal blocks in one track
have a unique signal block number stored in the third block sections of the signal
blocks. Now, all the signal blocks in a track can be identified by their unique signal
block number.
[0086] Signal block numbering the signal blocks as described above has a number of advantages.
Numbering the signal blocks open the possibility to shuffle signal blocks in an order
different from their original order, as long as the shuffling is done within a group
of signal blocks identified by unique signal block numbers. By detecting the signal
block numbers upon reproduction, a deshuffling can be carried out on the shuffled
signal blocks so as to obtain the original sequence order of the signal blocks.
[0087] Another measure that can be carried out is repeating a signal block, for the reason
that the recording and subsequent reproduction of the information included in the
signal block require a higher protection against transmission errors. Repeated signal
blocks will have the same signal block numbers so that they are identifiable upon
reproduction.
[0088] Further, upon detection of the signal block numbers, it can be detected whether a
signal block has been lost because of transmission errors occurring during the subsequent
recording and reproduction step. When missing a signal block number in a sequence
of signal block numbers, it can be decided that the signal block having the signal
block number that has been missed is lost. Upon such detection, an error correction
or concealment can be carried out so as to correct or conceal the missing signal block.
[0089] Next, an explanation will be given of the functioning of the 'trick play' processing
units 16 and 62 in the recording arrangement of figure 6 and the reproducing arrangement
of figure 7 respectively. For carrying out a trick mode (or feature mode) reproduction
with the reproduction arrangement, the record carrier 40 is transported with a speed
other than the nominal transport speed. Figure 16 shows the record carrier 40 having
a number of slant tracks recorded on it. Figure 16 also shows a path, denoted by the
reference numeral 120, via which path the reading head 52 scans the record carrier
in said trick mode. Generally, the information in the tracks is recorded by at least
two heads having gaps of different azimuth angles, so that even numbered tracks have
the one azimuth and odd numbered tracks have the other azimuth. That means that, when
scanning the record carrier along the path 120, the head 52, which head has one of
the two azimuth angles, will be able to read information from only the even numbered
or only the odd numbered tracks.
[0090] In order to enable a reproduction of video information during a trick play mode,
especially in the case of video information being recorded in a data reduced form,
it is required to add special trick play information in special locations in the tracks
such that those locations are scanned by the head 52 for the various transport speeds
for the record carrier that are possible in a trick play mode. This trick play information
is special video information recorded in addition to the normal play video information
that has been recorded in the tracks in the way described above. As a consequence
some of the signal blocks in a track comprise this trick play information, which should
be scanned and read by the head 52 in the trick play mode.
[0091] It should be noted here that the MPEG data, as far as the video data in the MPEG
datastream is concerned, comprises data reduced video information. To realize such
data reduced video information the information corresponding to one picture is intra
encoded so as to obtain so called I-frames. A higher data reduction can be obtained
by carrying out an interframe encoding on at least two subsequent pictures, resulting
in an I-frame for the first picture and a P-frame for the second picture. For recreating
the two pictures an intraframe decoding, inverse to the intraframe encoding, must
be carried out on the I-frame information, so as to regenerate the first picture,
and an interframe decoding, inverse to the interframe encoding, must be carried out
using both the I-frame information and the P-frame information, so as to regenerate
the second picture.
[0092] In a trick mode, only I-frame information can be used to regenerate a video signal,
as retrieving not only the I-frame information but also the corresponding P-frame
information so as to realize an interframe decoding, is not possible. Therefore, in
order to obtain the 'trick play' information, only the information stored in I-frames
included in the serial MPEG datastream is extracted and used as 'trick play' data.
[0093] It can be said that in a special location in a track, such as in the location indicated
by the hatched area 122 in the track 124 in figure 16, a number of signal blocks are
inserted that comprise the 'trick play' information. Figure 17 shows the sequence
of signal blocks in the track 124. The hatched area 122 in figure 16 is formed by
the sequence of signal blocks SB
i to SB
j inclusive in the sequence given in figure 17. The third block sections TB in the
signal blocks comprised in the trick play area 122 of the track now comprise an indication
that the signal blocks comprise trick mode information. This indication information
is denoted by 'T' in the third block sections TB3 of the signal blocks SB
i to SB
j inclusive. The signal blocks stored in the track prior to the trick play area 122,
as well as the signal blocks stored in the track after the trick play area 122 comprise
information indicating that the information stored in the signal blocks is normal
play information. This indication information is denoted by 'N' in the third block
sections TB3 in the signal blocks SB
i-2, SB
i-1, SB
j+1.
[0094] The 'trick play' processing unit 16 of figure 6 is thus capable of deriving the trick
play information from the MPEG datastream applied to its input 17, storing the trick
play information in those signal blocks that are specifically meant for storing the
trick play information in a specific location in a track and for inserting the indication
information indicating that the signal block is a signal block in which trick mode
information is stored in the third block sections of those signal blocks. The 'normal
play' processing unit 14 will further be capable of storing the indication information
indicating that the signal blocks generated by the unit 14 comprise normal play information,
in the third block sections of those signal blocks.
[0095] When the reproducing arrangement is switched into its trick mode, the trick play'
processing unit 62 will be capable of detecting those signal blocks that have the
'T' identification stored in their third block sections and to retrieve the information
from those signal blocks for further processing so as to realize a reviewing option
during the trick mode.
[0096] It should be noted that, although the invention has been described in the foregoing
using embodiments of recording arrangements of the helical scan type, this should
not be interpreted restrictively. The invention is equally well applicable to recording
arrangements of the linear recording type, or to recording arrangements for recording
information on disk like record carriers.
References
[0097]
(1) European patent application no EP-A-492,704 (PHN 13.546)
(2) European patent application no. 93.202.950 (EP-A-595 411) (PHN 14.241)
(3) European patent application no. 93.201.263 (PHN 14.449)
(4) Grand Alliance HDTV System Specification, Draft document, February 22, 1994.
(5) US patent specification no. US-A-5,142,421 (PHN 13.537)
1. Recording arrangement for recording an information signal in tracks on a record carrier
(40), the recording arrangement comprising
- an input terminal (11) for receiving the information signal,
- channel encoding means (12-34) for channel encoding the information signal so as
to obtain a channel signal suitable for recording in a track on said record carrier,
the channel signal comprising subsequent signal blocks (SB
i) having a predetermined fixed length, each signal block comprising a first block
section which comprises a synchronisation signal and a second block section (Fig.
4) which comprises a number of channel bytes,
- writing means (36) for writing the channel signal in the track,
characterized in that the recording arrangement is adapted to record an information signal in the form
of an MPEG information signal in accordance with an MPEG format, the MPEG information
signal comprising subsequent transport packets (P
k-1, P
k, P
k+1) having a predetermined fixed length, that the channel encoding means are adapted
to store information included in x transport packets of the MPEG information signal
in the second block sections of a group of y signal blocks of the channel signal,
that the second block sections of the signal blocks comprise a third block section
(TB3.j), and that the channel encoding means are further adapted to generate sequence
number information and store said sequence number information in the third block section
of the second block section, said sequence number information relating to a sequence
number of a signal block in a group of y signal blocks, and that x and y are integer
constants for which hold x≥1 and y>1.
2. Recording arrangement as claimed in claim 1, characterized in that the channel encoding means (14, 16) are adapted to store information included in
x transport packets (Pk-1, Pk, Pk+1) of the MPEG information signal in the second block sections of a first group of
y first signal blocks (SBi) of said signal blocks of the channel signal so as to enable a normal play mode using
video information stored in said first group of y first signal blocks during a normal
play reproduction mode, the channel encoding means (16) further being adapted to retrieve
a trick mode video signal from the MPEG information signal and being adapted to store
said trick mode video signal in second block sections of a second group of z second
signal blocks of said signal blocks of the channel signal so as to enable a trick
play mode using the video information stored in said second signal blocks, that the
second block sections of at least one signal block in each first and second group
of first and second signal blocks respectively comprise a third block section (TB3.j)
for storing identification information indicating whether the group comprises first
signal blocks or second signal blocks,
and that z is an integer such that z>1.
3. Recording arrangement as claimed in claim 1 or 2 characterized in that the second block sections of at least those signal blocks (SBi) in a group ofy signal blocks that comprises the start portion of a transport packet
comprise a third block section (TB3.j) for storing sequence number information relating
to a transport packet sequence number (k) corresponding to the transport packet (Pk) having its start portion stored in the second block section of the signal block.
4. Recording arrangement as claimed in claim 2, characterized in that the second block sections of all signal blocks in each first and second group of
first and second signal blocks respectively comprise a third block section (TB3.j)
for storing identification information indicating whether the group comprises first
signal blocks or second signal blocks.
5. Recording arrangement as claimed in claim 4, characterized in that the second block sections of a group of y signal blocks each comprise a third block
section for storing sequence number information relating to a transport packet sequence
number corresponding to the transport packet of which information is stored in said
signal block.
6. Recording arrangement as claimed in claim 1, 2, or 3, characterized in that the recording arrangement comprises detection means for detecting the moment of receipt
of the transport packets and for generating timing information for each transport
packet received, the timing information for a transport packet corresponding to said
moment of receipt of said transport packet, that the second block sections of at least
those signal blocks in a group of y signal blocks that comprises the start portion
of a transport packet comprise a third block section (TB3.j) for storing the timing
information for said transport packet (Pk) having its start portion stored in the second block section of the signal block.
7. Recording arrangement as claimed in claim 6, characterized in that the second block sections of a group of y signal blocks each comprise a third block
section (TB3.j) for storing the timing information corresponding to the transport
packet which has information stored in the second block section of said signal block.
8. Recording arrangement as claimed in anyone of the preceding claims, characterized in that y>x.
9. Record carrier having an information signal recorded on it in tracks on said record
carrier (40), the signal recorded in the tracks being in the form of a channel encoded
information signal, the channel encoded information signal comprising subsequent signal
blocks (SBi) having a predetermined fixed length, each signal block comprising a first block
section which comprises a synchronisation signal and a second block section (Fig.
4) which comprises a number of channel bytes, characterized in that the record carrier has an MPEG information signal in accordance with an MPEG format
recorded in its tracks, the MPEG information signal comprising subsequent transport
packets (Pk-i,Pk,Pk+1) having a predetermined fixed length, information included in x transport packets
of the MPEG information signal being included in the second block sections of a group
of y signal blocks of the channel encoded information signal, the second block section
of signal blocks comprising a third block section (TB3.j), sequence number information
being stored in said the third block section of the second block section, said sequence
number information relating to a sequence number of the signal blocks in a group of
y signal blocks, and that x and y are integer constants for which hold x≥1 and y>1.
10. Record carrier as claimed in claim 9 or 10, characterized in that the channel signal recorded in a track comprises a first group of y first signal
blocks so as to enable a normal play mode using the video information stored in said
first group of y first signal blocks during a normal play reproduction mode, and comprises
a second group of z second signal blocks in which a trick mode video signal is stored
so as to enable a trick play mode using the video information stored a said second
group of z second signal blocks, that indication information indicating whether a
group comprises first signal blocks or second signal blocks is stored in the third
block sections (TB3.j) of at least one signal block of the first and second group.
11. Record carrier as claimed in claim 9 or 10, characterized in that, the third block section (TB3.j) of the second block sections of at least those signal
blocks in a group of y signal blocks that comprises the start portion of a transport
packet comprise information relating to a transport packet sequence number (k) corresponding
to the transport packet (Pk) having its start portion stored in the second block section of the signal block.
12. Record carrier as claimed in claim 9,10 or 11
characterized in that the third block section (TB3.j) of the second block sections of at least those signal
blocks in a group of y signal blocks that comprises the start portion of a transport
packet comprise timing information for said transport packet having its start portion
stored in the second block section of the signal block.
- second retrieving means (90) for retrieving said sequence number information from
the third block sections (TB3.j) of the signal in said track.
13. Reproducing arrangement for reproducing an information signal that has been recorded
in the form of a channel signal in tracks on a record carrier (40), the reproducing
arrangement comprising
- reading means (50) for reading the channel signal from a track,
the channel signal comprising subsequent signal blocks (SBi) having a predetermined fixed length, each signal block comprising a first block
section which comprises a synchronisation signal and a second block section (Fig.
4) which comprises a number of channel bytes,
- channel decoding means (54-66) for channel decoding the channel signal into the
information signal,
- an output terminal (68) for applying the information signal,
characterized in that the reproducing arrangement is adapted to reproduce an MPEG information signal in
accordance with an MPEG format from the record carrier, the MPEG information signal
comprising subsequent transport packets (P
k-1,P
k,P
k+1) having a predetermined fixed length, information comprised in x transport packets
of the MPEG information signal being stored in the second block sections of a group
of y signal blocks of the channel signal, that x and y are integer constants for which
hold x≥1 and y>1, that the second block section of signal blocks comprise a third
block section (TB3.j), for storing sequence number information relating to a sequence
number of the signal blocks, the reproducing arrangement further comprising
- first retrieving means (60) for retrieving the information comprised in the x transport
packets of the MPEG information signal from the group of y signal blocks,
- second retrieving means (90) for retrieving said sequence number information from
the third block sections (TB3.j) of the signal in said track.
14. Reproducing arrangement as claimed in claim 13
characterized in that information comprised in x transport packets of the MPEG information signal is stored
in the second block sections of a first group of y first signal blocks of the channel
signal so as to enable a normal play mode using the video information stored in said
first group of y first signal blocks during a normal play reproduction mode,
a trick mode video signal being stored in a second group of z second block sections
of second signal blocks of said signal blocks of the channel signal so as to enable
a trick play mode using the video information stored in said second group of second
signal blocks, that the second block sections of at least one first and second signal
block in the first and second group each comprise a third block section for storing
indication information indicating whether the group comprise first signal blocks or
second signal blocks,
the reproducing arrangement further comprising
- first retrieving means (60, 62) for retrieving in said normal play mode the video
information of the x transport packets of the MPEG information signal from the first
group of y first signal blocks, and for retrieving in said trick play mode the trick
mode video signal from the second group of z second signal blocks, in response to
a first or a second control signal respectively supplied by
- second retrieving means (90) for retrieving the indication information indicating
whether the group comprise first signal blocks or second signal blocks from the third
block sections (TB3.j) of the at least one signal block in the first and second groups
respectively, the second retrieving means being further adapted to generate said first
and second control signal in response thereto.
15. Reproducing arrangement as claimed in claim 13 or 14
characterized in that the second block sections of at least those signal blocks in a group of y signal
blocks that comprises the start portion of a transport packet comprise a third block
section for storing sequence number information relating to a transport packet sequence
number corresponding to the transport packet having its start portion stored in the
second block section of the signal block,
the reproducing arrangement further comprising
- first retrieving means (60) for retrieving the information comprised in the x transport
packets of the MPEG information signal from the group of y signal blocks,
- second retrieving means (90) for retrieving the sequence number information relating
to the transport packet sequence number from a third block section (TB3.j) of a signal
block in the group of y signal blocks.
16. Reproducing arrangement as claimed in claim 13,14 or 15,
characterized in that x and y are integers such that x≥1 and y>1, that the second block sections of at
least those signal blocks in a group of y signal blocks that comprises the start portion
of a transport packet comprise a third block section for storing timing information
for said transport packet having its start portion stored in the second block section
of the signal block, the reproducing arrangement further comprising
- first retrieving means (60) for retrieving the information comprised in the x transport
packets of the MPEG information signal from the group of y signal blocks,
- second retrieving means (90) for retrieving the timing information from a third
block (TB3.j) section of a signal block in the group of y signal blocks.
17. Reproducing arrangement as claimed in anyone of the claims 13 to 16,
characterized in that y>x.
18. Method for recording an information signal in tracks on a record carrier, the recording
method comprising the steps of
- receiving the information signal,
- channel encoding the information signal into a channel signal, the channel signal
comprising subsequent signal blocks (SBi) having a predetermined fixed length, each signal block comprising a first block
section which comprises a synchronisation signal and a second block section which
comprises a number of channel bytes,
- writing the channel signal in the tracks on the record carrier,
characterized in that recording method is for recording an information signal in the form of an MPEG information
signal in accordance with an MPEG format on the record carrier, the MPEG information
signal comprising subsequent transport packets having a predetermined fixed length,
that the channel encoding step comprises the substeps of
- storing information included in x transport packets of the MPEG information signal
in the second block sections of a group of y signal blocks of the channel signal,
that the second block sections of the signal blocks comprise a third block section
(TB3.j), and
- storing sequence number information in said third block section, said sequence number
information relating to a sequence number of the signal blocks in a group of y signal
blocks, and that x and y are integer constants for which hold x≥1 and y>1.
1. Aufzeichnungsanordnung zum Aufzeichnen eines Informationssignals in Spuren auf einem
Aufzeichnungsträger (40), wobei diese Aufzeichnungsanordnung die nachfolgenden Elemente
umfasst:
- eine Eingangsklemme (11) zum Empfangen des Informationssignals,
- Kanalcodierungsmittel (12-34) zur Kanalcodierung des Informationssignals zum Erhalten
eines Kanalsignals, geeignet zum Aufzeichnen in einer Spur auf dem genannten Aufzeichnungsträger,
wobei das Kanalsignal aufeinander folgende Signalblöcke (SB) einer vorbestimmten
festen Länge umfasst, wobei jeder Signalblock einen ersten Blockteil aufweist, der
ein Synchronisationssignal enthält, und einen zweiten Blockteil aufweist (Fig. 4),
der eine Anzahl Kanalbytes enthält,
- Schreibmittel (36) zum Schreiben des Kanalsignals in der Spur,
dadurch gekennzeichnet, dass die Aufzeichnungsanordnung dazu vorgesehen ist, ein Informationssignal in Form eines
MPEG-Informationssignals entsprechend einem MPEG-Format aufzuzeichnen, wobei das MPEG-Informationssignal
aufeinander folgende Transportpakete (P
k-1, P
k, P
k+1) einer vorbestimmten festen Länge umfasst, dass die Kanalcodierungsmittel dazu vorgesehen
sind, Information zu speichern, die in x Transportpaketen des MPEG-Informationssignals
in den zweiten Blockteilen einer Gruppe von y Signalblöcken des Kanalsignals vorhanden
sind, dass die zweiten Blockteile der Signalblöcke einen dritten Blockteil (TB3.j)
umfassen, und dass die Kanalcodierungsmittel weiterhin dazu vorgesehen sind, Sequenznummerinformation
zu erzeugen und die genannte Sequenznummerinformation in dem dritten Blockteil des
zweiten Blockteils zu speichern, wobei die genannte Sequenznummerinformation sich
auf eine Sequenznummer einer Signalblocks in einer Gruppe von y Signalblöcken bezieht,
und dass x und y ganzzahlige Konstanten sind, für die gilt: x ≥1 und y > 1.
2. Aufzeichnungsanordnung nach Anspruch 1, dadurch gekennzeichnet, dass die Kanalcodierungsmittel (14, 16) dazu vorgesehen sind, Information zu speichern,
die in x Transportpaketen (Pk-1, Pk, Pk+1) des MPEG-Informationssignals in den zweiten Blockteilen einer ersten Gruppe von
y ersten Signalblöcken (SBi) der genannten Signalblöcke des Kanalsignals vorhanden sind, um eine Normal-Spiel-Mode
zu ermöglichen, wobei während einer Normal-Spiel-Wiedergabemode Videoinformation verwendet
wird, die in der genannten ersten Gruppe von y ersten Signalblöcken gespeichert ist,
wobei die Kanalcodierungsmittel (16) weiterhin dazu vorgesehen sind, aus dem MPEG-Informationssignal
ein Trick-Mode-Videosignal wiederzugewinnen und dazu vorgesehen sind, das genannte
Trick-Mode-Videosignal in zweiten Blockteilen einer zweiten Gruppe von z zweiten Signalblöcken
der genannten Signalblöcke des Kanalsignals zu speichern, um eine Trick-Spiel-Mode
zu ermöglichen, wobei die Videoinformation verwendet wird, die in den genannten zweiten
Signalblöcken gespeichert ist, dass die zweiten Blockteile wenigstens eines Signalblocks
in jeder ersten und zweiten Gruppe von ersten und zweiten Blöcken einen dritten Blockteil
(TB3.j) enthalten zum Speichern von Identifikationsinformation, die angibt, ob die
Gruppe erste Signalblöcke oder zweite Signalblöcke enthält,
und dass z eine ganze Zahl ist, so dass z > 1 ist.
3. Aufzeichnungsanordnung nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass die zweiten Blockteile wenigstens derjenigen Signalblöcke (SBi) in einer Gruppe von y Signalblöcken, die den Startteil eines Transportpakets enthält,
einen dritten Blockteil (TB3.j) enthalten zur Speicherung von Sequenznummerinformation
in Bezug auf eine Transportpaketsequenznummer (k) entsprechend dem Transportpaket
(Pk), wobei der Startteil in dem zweiten Blockteil des Signalblocks gespeichert ist.
4. Aufzeichnungsanordnung nach Anspruch 2, dadurch gekennzeichnet, dass die zweiten Blockteile aller Signalblöcke in jeder ersten und zweiten Gruppe der
ersten und zweiten Signalblöcke einen dritten Blockteil (TB3.j) enthalten zur Speicherung
von Identifikationsinformation, die angibt, ob die Gruppe erste Signalblöcke oder
zweite Signalblöcke aufweist.
5. Aufzeichnungsanordnung nach Anspruch 4, dadurch gekennzeichnet, dass die zweiten Blockteile einer Gruppe von y Signalblöcken je einen dritten Blockteil
aufweisen zur Speicherung von Sequenznummerinformation in Bezug auf eine Transportpaketsequenznummer
entsprechend dem Transportpaket, dessen Information in dem genannten Signalblock gespeichert
ist.
6. Aufzeichnungsanordnung nach Anspruch 1, 2 oder 3, dadurch gekennzeichnet, dass die Aufzeichnungsanordnung Detektionsmittel aufweist zum Detektieren des Zeitpunktes
des Empfangs der Transportpakete und zum Erzeugen von Zeitinformation für jedes empfangene
Transportpaket, wobei die Zeitinformation für ein Transportpaket dem genannten Zeitpunkt
des Empfangs des genannten Transportpakets entspricht, dass die zweiten Blockteile
wenigstens derjenigen Signalblöcke in einer Gruppe von y Signalblöcken, die den Startteil
eines Transportpakets enthält, einen dritten Blockteil (TB3.j) enthalten zur Speicherung
der Zeitinformation für das genannte Transportpaket (Pk), dessen Startteil in dem zweiten Blockteil des Signalblocks gespeichert ist.
7. Aufzeichnungsanordnung nach Anspruch 6. Dadurch gekennzeichnet, dass die zweiten Blockteile einer Gruppe von y Signalblöcken je einen dritten Blockteil
(TB3.j) enthalten zur Speicherung der Zeitinformation entsprechend dem Transportpaket,
dessen Information in dem zweiten Blockteil des genannten Signalblocks gespeichert
ist.
8. Aufzeichnungsanordnung nach einem der vorstehenden Ansprüche, dadurch gekennzeichnet, dass y > x ist.
9. Aufzeichnungsträger, wobei auf diesem Aufzeichnungsträger (40) ein Informationssignal
in Spuren aufgezeichnet ist, wobei das in den Spuren aufgezeichnete Signal in Form
eines kanalcodierten Informationssignals ist, wobei das kanalcodierte Informationssignal
aufeinander folgende Signalblöcke (SB;) einer vorbestimmten festen Länge aufweist,
wobei jeder Signalblock einen ersten Blockteil umfasst, der ein Synchronisationssignal
enthält, und einen zweiten Blockteil (Fig. 4) umfasst, der eine Anzahl Kanalbytes
aufweist, dadurch gekennzeichnet, dass der Aufzeichnungsträger ein in seinen Spuren aufgezeichnetes MPEG-Informationssignal
entsprechend einem MPEG-Format enthält, wobei das MPEG-Informationssignal aufeinander
folgende Transportpakete (Pk-i, Pk, Pk+1) einer vorbestimmten festen Länge enthält, wobei Information in x Transportpaketen
des MPEG-Informationssignals in den zweiten Blockteilen einer Gruppe von y Signalblöcken
des kanalcodierten Informationssignals vorhanden ist, wobei der zweite Blockteil mit
Signalblöcken einen dritten Blockteil (TB3.j) enthält, wobei Sequenznummerinformation
in dem dritten Blockteil des zweiten Blockteils gespeichert ist, wobei die genannte
Sequenznummerinformation sich auf eine Sequenznummer der Signalblöcke in einer Gruppe
von y Signalblöcken bezieht, und dass x und y ganzzahlige Konstanten sind, für die
gilt: x ≥1 und y > 1.
10. Aufzeichnungsträger nach Anspruch 9, dadurch gekennzeichnet, dass das in einer Spur aufgezeichnete Kanalsignal eine erste Gruppe von y ersten Signalblöcken
umfasst um eine Normal-Spiel-Mode zu ermöglichen, wobei während einer Normal-Spiel-Wiedergabemode
die Videoinformation verwendet wird, die in der genannten ersten Gruppe von y ersten
Signalblöcken gespeichert ist, und eine zweite Gruppe von z zweiten Signalblöcken
umfasst, in der ein Trick-Mode-Videosignal gespeichert ist um eine Trick-Spiel-Mode
zu ermöglichen, wobei die in der genannten Gruppe von z zweiten Signalblöcken gespeicherte
Videoinformation verwendet wird, wobei die Information angibt, ob eine Gruppe erste
Signalblöcke oder zweite Signalblöcke aufweist, die in den dritten Blockteilen (TB3.j)
wenigstens eines Signalblocks der ersten und zweiten Gruppe gespeichert sind.
11. Aufzeichnungsträger nach Anspruch 9, dadurch gekennzeichnet, dass der dritte Blockteil (TB3.j) der zweiten Blockteile wenigstens derjenigen Signalblöcke
in einer Gruppe von y Signalblöcken, die den Startteil eines Transportpakets aufweist,
Information in Bezug auf eine Transportpaketsequenznummer (k) entsprechend dem Transportpaket
(Pk) enthält, dessen Startteil in dem zweiten Blockteil des Signalblocks gespeichert
ist.
12. Aufzeichnungsträger nach Anspruch 9, 10 oder 11, dadurch gekennzeichnet, dass der dritte Blockteil (TB3.j) der zweiten Blockteile wenigstens derjenigen Signalblöcke
in einer Gruppe von y Signalblöcken, die den Startteil eines Transportpakets enthält,
Zeitinformation für das genannte Transportpaket aufweist, dessen Startteil in dem
zweiten Blockteil des Signalblocks gespeichert ist.
13. Wiedergabeanordnung zum Wiedergeben eines Informationssignals, das in Form eines Kanalsignals
in Spuren auf einem Aufzeichnungsträger (4) aufgezeichnet worden ist, wobei die Wiedergabeanordnung
die nachfolgenden Elemente umfasst:
- Lesemittel (50) zum Auslesen des Kanalsignals aus einer Spur,
wobei das Kanalsignal aufeinander folgende Signalblöcke (SB
i) einer vorbestimmten festen Länge aufweist, wobei jeder Signalblock einen ersten
Blockteil enthält, der ein Synchronisationssignal aufweist, und einen zweiten Blockteil
(Fig. 4), der eine Anzahl Kanalbytes umfasst,
- Kanaldecodierungsmittel (54-66) zur Kanaldecodierung des Kanalsignals in das Informationssignal,
- eine Ausgangsklemme (68) zum Liefern des Informationssignals,
dadurch gekennzeichnet, dass die Wiedergabeanordnung dazu vorgesehen ist, ein MPEG-Informationssignal entsprechend
einem MPEG-Format aus dem Aufzeichnungsträger wiederzugeben, wobei das MPEG-Informationssignal
aufeinander folgende Transportpakete (P
k-1, P
k, P
k+1) einer vorbestimmten festen Länge enthält, wobei die Information in x Transportpaketen
des MPEG-Informationssignals in den zweiten Blockteilen einer Gruppe von y Signalblöcken
des Kanalsignals gespeichert ist, dass x und y ganzzahlige Konstanten sind, für die
gilt: x ≥1 und y > 1, dass der zweite Blockteil der Signalblöcke einen dritten Blockteil
(TB3.j) enthält zur Speicherung von Sequenznummerinformation in Bezug auf eine Sequenznummer
der Signalblöcke, wobei die Wiedergabeanordnung weiterhin die nachfolgenden Elemente
umfasst:
- erste Erfassungsmittel (60) zum Erfassen der Information in den x Transportpaketen
des MPEG-Informationssignals aus der Gruppe von y Signalblöcken,
- zweite Erfassungsmittel (90) zum Erfassen der genannten Sequenznummerinformation
aus den dritten Blockteilen (TB3.j) des Signals in der genannten Spur.
14. Wiedergabeanordnung nach Anspruch 13,
dadurch gekennzeichnet, dass Information in x Transportpaketen des MPEG-Informationssignals in den zweiten Blockteilen
der ersten Gruppe von y ersten Signalblöcken des Kanalsignals gespeichert ist um eine
Normal-Spiel-Mode zu ermöglichen, wobei während einer Normal-Spiel-Wiedergabemode
die in der genannten ersten Gruppe von y ersten Signalblöcken gespeicherte Videoinformation
verwendet wird,
wobei ein Trick-Mode-Videosignal in einer zweiten Gruppe von z zweiten Blockteilen
von zweiten Signalblöcken der genannten Signalblöcke des Kanalsignals gespeichert
ist um eine Trick-Spiel-Mode zu ermöglichen, wobei die in der genannten zweiten Gruppe
von zweiten Signalblöcken gespeicherte Videoinformation verwendet wird, dass die zweiten
Blockteile wenigstens eines zweiten Signalblocks in der ersten und zweiten Gruppe
je einen dritten Blockteil umfassen zur Speicherung von Indikationsinformation, die
angibt, ob die Gruppe erste Signalblöcke oder zweite Signalblöcke aufweist,
wobei die Wiedergabeanordnung weiterhin die nachfolgenden Elemente umfasst:
- erste Erfassungsmittel (60, 62) zum in der genannten Normal-Spiel-Mode Erfassen
der Videoinformation der x Transportpakete des MPEG-Informationssignals aus der ersten
Gruppe von y ersten Signalblöcken, und zum in der genannten Trick-Spiel-Mode Erfassen
des Trick-Mode-Videosignals aus der zweiten Gruppe von z zweiten Signalblöcken, und
zwar in Reaktion auf ein erstes oder ein zweites Steuersignal, das geliefert wird
von
- zweiten Erfassungsmitteln (90) zum Erfassen der Indikationsinformation, die angibt,
ob die Gruppe erste Signalblöcke oder zweite Signalblöcke aus den dritten Blockteilen
(TB3.j) des wenigstens einen Signalblocks in der ersten bzw. zweiten Gruppe enthält,
wobei die zweiten Erfassungsmittel weiterhin dazu vorgesehen sind, in Reaktion darauf
das genannte erste und zweite Steuersignal zu erzeugen.
15. Wiedergabeanordnung nach Anspruch 13 oder 14,
dadurch gekennzeichnet, dass die zweiten Blockteile wenigstens derjenigen Signalblöcke in einer Gruppe von y Signalblöcken,
die den Startteil eines Transportpakets enthält, einen dritten Blockteil aufweist
zur Speicherung von Sequenznummerinformation in Bezug auf eine Transportpaketsequenznummer
entsprechend dem Transportpaket, dessen Startteil in dem zweiten Blockteil des Signalblocks
gespeichert ist,
wobei die Wiedergabeanordnung weiterhin die nachfolgenden Elemente umfasst:
- erste Erfassungsmittel (60) zum Erfassen der Information in den x Transportpaketen
des MPEG-Informationssignals aus der Gruppe von y Signalblöcken,
- zweite Erfassungsmittel (90) zum Erfassen der Sequenznummerinformation in Bezug
auf die Transportpaketsequenznummer aus einem dritten Blockteil (TB3.j) eines Signalblocks
in der Gruppe von y Signalblöcken.
16. Wiedergabeanordnung nach Anspruch 13, 14 oder 15,
dadurch gekennzeichnet, dass x und y ganze Zahlen sind, so dass x ≥1 und y > 1 ist, dass die zweiten Blockteile
wenigstens derjenigen Signalblöcke in einer Gruppe von y Signalblöcken, die den Startteil
eines Transportpakets enthält, einen dritten Blockteil aufweisen zur Speicherung von
Zeitinformation für das genannte Transportpaket, dessen Startteil in dem zweiten Blockteil
des Signalblocks gespeichert ist, wobei die Wiedergabeanordnung weiterhin die nachfolgenden
Elemente umfasst:
- erste Erfassungsmittel (60) zum Erfassen der Information in den x Transportpaketen
des MPEG-Informationssignals aus der Gruppe von y Signalblöcken,
- zweite Erfassungsmittel (90) zum Erfassen der Zeitinformation aus einem dritten
Blockteil (TB3.j) eines Signalblocks in der Gruppe von y Signalblöcken.
17. Wiedergabeanordnung nach einem der Ansprüche 13 bis 16, dadurch gekennzeichnet, dass y > x ist.
18. Verfahren zum Aufzeichnen eines Informationssignals in Spuren auf einem Informationsträger,
wobei dieses Verfahren die nachfolgenden Verfahrensschritte umfasst:
- das Empfangen des Informationssignals,
- das Kanalcodieren des Informationssignals in ein Kanalsignal,
wobei das Kanalsignal aufeinander folgende Signalblöcke (SB
i) einer vorbestimmten festen Länge aufweist, wobei jeder Signalblock einen ersten
Blockteil enthält, der ein Synchronisationssignal aufweist, und einen zweiten Blockteil
enthält, der eine Anzahl Kanalbytes aufweist,
- das Schreiben das Kanalsignals in der Spur auf dem Aufzeichnungsträger,
dadurch gekennzeichnet, dass das Aufzeichnungsverfahren dient zum Aufzeichnen eines Informationssignals in Form
eines MPEG-Informationssignals entsprechend einem MPEG-Format auf dem Aufzeichnungsträger,
wobei das MPEG-Informationssignal aufeinander folgende Transportpakete einer vorbestimmten
festen Länge aufweist, dass der Kanalcodierungsschritt die nachfolgenden Teilschritte
umfasst:
- das Speichern von Information in x Transportpaketen des MPEG-Informationssignals
in den zweiten Blockteilen einer Gruppe von y Signalblöcken des Kanalsignals, dass
die zweiten Blockteile der Signalblöcke einen dritten Blockteil (TB3.j) enthalten,
und
- das Speichern von Sequenznummerinformation in dem genannten dritten Blockteil, wobei
die genannte Sequenznummerinformation sich auf eine Sequenznummer der Signalblöcke
in einer Gruppe von y Signalblöcken bezieht, und dass x und y ganzzahlige Konstanten
sind, für die gilt: x ≥1 und y > 1.
1. Montage d'enregistrement pour enregistrer un signal d'information dans des pistes
sur un support d'enregistrement (40), le montage d'enregistrement comprenant:
- une borne d'entrée (11) pour recevoir le signal d'information;
- des moyens de codage de canal (12-34) pour coder par codage de canal le signal d'information
de manière à obtenir un signal de canal approprié à l'enregistrement dans une piste
sur ledit support d'enregistrement;
le signal de canal comprenant des blocs de signal successifs (SB
i) d'une longueur fixe prédéterminée, chaque bloc de signal comprenant une première
section de bloc qui comprend un signal de synchronisation et une deuxième section
de bloc (figure 4) qui comprend un certain nombre d'octets de canal;
- des moyens d'écriture (36) pour écrire le signal de canal dans la piste,
caractérisé en ce que le montage d'enregistrement est adapté à enregistrer un signal d'information sous
la forme d'un signal d'information MPEG suivant un format MPEG, le signal d'information
MPEG comprenant des paquets de transport successifs (P
k-1,P
k,P
k+1) d'une longueur fixe prédéterminée,
en ce que les moyens de codage de canal sont adaptés à mémoriser des informations comprises
dans x paquets de transport du signal d'information MPEG dans les deuxièmes sections
de bloc d'un groupe de y blocs de signal du signal de canal,
en ce que les deuxièmes sections de bloc des blocs de signal comprennent une troisième section
de bloc (TB3.j), et
en ce que les moyens de codage de canal sont en outre adaptés à produire des informations de
numéro de séquence et à mémoriser lesdites informations de numéro de séquence dans
la troisième section de bloc de la deuxième section de bloc, lesdites informations
de numéro de séquence ayant rapport à un numéro de séquence d'un bloc de signal dans
un groupe de y blocs de signal, et
en ce que x et y sont des constantes entières pour lesquelles x≥1 et y>1.
2. Montage d'enregistrement selon la revendication 1, caractérisé en ce que les moyens de codage de canal (14, 16) sont adaptés à mémoriser des informations
incluses dans x paquets de transport (Pk-1,Pk,Pk+1) du signal d'information MPEG dans les deuxièmes sections de bloc d'un premier groupe
de y premiers blocs de signal (SBi) desdits blocs de signal du signal de canal de
manière à permettre un mode de lecture normale en utilisant des informations vidéo
mémorisées dans ledit premier groupe de y premiers blocs de signal pendant un mode
de reproduction à lecture normale, les moyens de codage de canal (16) étant en outre
adaptés à récupérer un signal vidéo en mode de fonctionnement truqué à partir du signal
d'information MPEG et étant adaptés à mémoriser ledit signal vidéo en mode de fonctionnement
truqué dans des deuxièmes sections de bloc d'un deuxième groupe de z deuxièmes blocs
de signal desdits blocs de signal du signal de canal de manière à permettre un mode
de lecture en mode de fonctionnement truqué en utilisant les informations vidéo mémorisées
dans lesdits deuxièmes blocs de signal, en ce que les deuxièmes sections de bloc d'au moins un bloc de signal dans chaque premier et
deuxième groupes de premiers et deuxièmes blocs de signal, respectivement, comprennent
une troisième section de bloc (TB3.j) pour mémoriser des informations d'identification
indiquant si le groupe comprend des premiers blocs de signal ou des deuxièmes blocs
de signal,
et en ce que z est un entier tel que z>1.
3. Montage d'enregistrement selon la revendication 1 ou 2, caractérisé en ce que les deuxièmes sections de bloc d'au moins les blocs de signal (SBi) dans un groupe
de y blocs de signal qui comprend la partie de début d'un paquet de transport comprennent
une troisième section de bloc (TB3.j) pour mémoriser des informations de numéro de
séquence ayant rapport à un numéro de séquence de paquet de transport (k) correspondant
au paquet de transport (Pk) dont la partie de début est mémorisée dans la deuxième section de bloc du bloc de
signal.
4. Montage d'enregistrement selon la revendication 2, caractérisé en ce que les deuxièmes sections de bloc de tous les blocs de signal dans chaque premier et
deuxième groupes de premiers et de deuxièmes blocs de signal, respectivement, comprennent
une troisième section de bloc (TB3.j) pour mémoriser des informations d'identification
indiquant si le groupe comprend des premiers blocs de signal ou des deuxièmes blocs
de signal.
5. Montage d'enregistrement selon la revendication 4, caractérisé en ce que les deuxièmes sections de bloc d'un groupe de y blocs de signal comprennent chacune
une troisième section de bloc pour mémoriser les informations de numéro de séquence
ayant rapport à un numéro de séquence de paquet de transport correspondant au paquet
de transport dont les informations sont mémorisées dans ledit bloc de signal.
6. Montage d'enregistrement selon la revendication 1, 2, ou 3, caractérisé en ce que le montage d'enregistrement comprend des moyens de détection pour détecter le moment
de réception des paquets de transport et pour produire des informations de cadencement
pour chaque paquet de transport reçu, les informations de cadencement pour un paquet
de transport correspondant audit moment de réception dudit paquet de transport, et
en ce que les deuxièmes sections de bloc d'au moins ces blocs de signal dans un groupe de y
blocs de signal qui comprend la partie de début d'un paquet de transport comprennent
une troisième section de bloc (TB3.j) pour mémoriser les informations de cadencement
pour ledit paquet de transport (Pk) dont la partie de début est mémorisée dans la deuxième section de bloc du bloc de
signal.
7. Montage d'enregistrement selon la revendication 6, caractérisé en ce que les deuxièmes sections de bloc d'un groupe de y blocs de signal comprennent chacune
une troisième section de bloc (TB3.j) pour mémoriser les informations de cadencement
correspondant au paquet de transport dont les informations sont mémorisées dans la
deuxième section de bloc dudit bloc de signal.
8. Montage d'enregistrement selon l'une quelconque des revendications précédentes 1 à
7, caractérisé en ce que y>x.
9. Support d'enregistrement comprenant un signal d'information enregistré sur celui-ci
dans des pistes sur ledit support d'enregistrement (40), le signal enregistré dans
les pistes étant sous la forme d'un signal d'information codé par codage de canal,
le signal d'information codé par codage de canal comprenant des blocs de signal successifs
(SBi) d'une longueur fixe prédéterminée, chaque bloc de signal comprenant une première
section de bloc qui comprend un signal de synchronisation et une deuxième section
de bloc (figure 4) qui comprend un certain nombre d'octets de canal, caractérisé en ce que le support d'enregistrement comprend un signal d'information MPEG suivant un format
MPEG enregistré dans ses pistes, le signal d'information MPEG comprenant des paquets
de transport successifs (Pk-1,Pk,Pk+1) d'une longueur fixe prédéterminée, des informations incluses dans x paquets de transport
du signal d'information MPEG étant incluses dans les deuxièmes sections de bloc d'un
groupe de y blocs de signal du signal d'information codé par codage de canal, la deuxième
section de bloc de blocs de signal comprenant une troisième section de bloc (TB3.j),
des informations de numéro de séquence étant mémorisées dans la troisième section
de bloc de la deuxième section de bloc, lesdites informations de numéro de séquence
ayant rapport à un numéro de séquence des blocs de signal dans un groupe de y blocs
de signal. et en ce que x et y sont des constantes entières pour lesquelles x≥1 et y>1.
10. Support d'enregistrement selon la revendication 9 ou 11, caractérisé en ce que le signal de canal enregistré dans une piste comprend un premier groupe de y premiers
blocs de signal de manière à permettre un mode de lecture normale en utilisant les
informations vidéo mémorisées dans ledit premier groupe de y premiers blocs de signal
pendant un mode de reproduction à lecture normale, et comprend un deuxième groupe
de z deuxièmes blocs de signal dans lesquels un signal vidéo en mode de fonctionnement
truqué est mémorisé de manière à permettre un mode de lecture en mode de fonctionnement
truqué en utilisant les informations vidéo mémorisées dans ledit deuxième groupe de
z deuxièmes blocs de signal, en ce que des informations d'indication indiquant si un groupe comprend des premiers blocs
de signal ou des deuxièmes blocs de signal sont mémorisées dans les troisièmes sections
de bloc (TB3.j) d'au moins un bloc de signal des premier et deuxième groupes.
11. Support d'enregistrement selon la revendication 9 ou 10, caractérisé en ce que la troisième section de bloc (TB3.j) des deuxièmes sections de bloc d'au moins ces
blocs de signal dans un groupe de y blocs de signal qui comprend la partie de début
d'un paquet de transport comprennent des informations ayant rapport à un numéro de
séquence de paquet de transport (k) correspondant au paquet de transport (Pk) dont la partie de début est mémorisée dans la deuxième section de bloc du bloc de
signal.
12. Support d'enregistrement selon la revendication 9, 10 ou 11, caractérisé en ce que la troisième section de bloc (TB3.j) des deuxièmes sections de bloc d'au moins ces
blocs de signal dans un groupe de y blocs de signal qui comprend la partie de début
d'un paquet de transport comprennent des informations de cadencement pour ledit paquet
de transport dont la partie de début est mémorisée dans la deuxième section de bloc
du bloc de signal.
13. Montage de reproduction pour reproduire un signal d'information qui a été enregistré
sous la forme d'un signal de canal dans des pistes sur un support d'enregistrement
(40), le montage de reproduction comprenant:
- des moyens de lecture (50) pour lire le signal de canal à partir d'une piste; le
signal de canal comprenant des blocs de signal successifs (SBi) d'une longueur fixe prédéterminée, chaque bloc de signal comprenant une première
section de bloc qui comprend un signal de synchronisation et une deuxième section
de bloc (figure 4) qui comprend un certain nombre d'octets de canal;
- des moyens de décodage de canal (54-66) pour décoder par décodage de canal le signal
de canal en signal d'information;
- une borne de sortie (68) pour appliquer le signal d'information;
caractérisé en ce que le montage de reproduction est adapté à reproduire un signal d'information MPEG suivant
un format MPEG à partir du support d'enregistrement, le signal d'information MPEG
comprenant des paquets de transport successifs (P
k-1,P
k,P
k+1) d'une longueur fixe prédéterminée, des informations comprises dans x paquets de
transport du signal d'information MPEG étant mémorisées dans les deuxièmes sections
de bloc d'un groupe de y blocs de signal du signal de canal,
en ce que x et y sont des constantes entières pour lesquelles x≥1 et y>1,
en ce que la deuxième section de bloc de blocs de signal comprend une troisième section de
bloc (TB3.j) pour mémoriser des informations de numéro de séquence ayant rapport à
un numéro de séquence des blocs de signal, le montage de reproduction comprenant en
outre:
- des premiers moyens de récupération (60) pour récupérer les informations comprises
dans les x paquets de transport du signal d'information MPEG à partir du groupe de
y blocs de signal;
- des deuxièmes moyens de récupération (90) pour récupérer lesdites informations de
numéro de séquence à partir des troisièmes sections de bloc (TB3.j) du signal dans
ladite piste.
14. Montage de reproduction selon la revendication 13,
caractérisé en ce que les informations comprises dans x paquets de transport du signal d'information MPEG
sont mémorisées dans les deuxièmes sections de bloc d'un premier groupe de y premiers
blocs de signal du signal de canal de manière à permettre un mode de lecture normale
en utilisant les informations vidéo mémorisées dans ledit premier groupe de y premiers
blocs de signal pendant un mode de reproduction à lecture normale; un signal vidéo
en mode de fonctionnement truqué étant mémorisé dans un deuxième groupe de z deuxièmes
sections de bloc de deuxièmes blocs de signal desdits blocs de signal du signal de
canal de manière à permettre un mode de lecture en mode de fonctionnement truqué en
utilisant les informations vidéo mémorisées dans ledit deuxième groupe de deuxièmes
blocs de signal,
en ce que les deuxièmes sections de bloc d'au moins le premier et le deuxième blocs de signal
dans le premier et le deuxième groupes comprennent chacune une troisième section de
bloc pour mémoriser des informations d'indication indiquant si le groupe comprend
des premiers blocs de signal ou des deuxièmes blocs de signal;
le montage de reproduction comprenant en outre:
- des premiers moyens de récupération (60, 62) pour récupérer dans ledit mode de lecture
normale les informations vidéo des x paquets de transport du signal d'information
MPEG à partir du premier groupe de y premiers blocs de signal, et pour récupérer dans
ledit mode de lecture en mode de fonctionnement truqué le signal vidéo en mode de
fonctionnement truqué à partir du deuxième groupe de z deuxièmes blocs de signal,
en réaction à un premier ou à un deuxième signal de commande, respectivement, fourni
par:
- des deuxièmes moyens de récupération (90) pour récupérer les informations d'indication
indiquant si le groupe comprend des premiers blocs de signal ou des deuxièmes blocs
de signal des troisièmes sections de bloc (TB3.j) du au moins un bloc de signal dans
les premier et deuxième groupes, respectivement, les deuxièmes moyens de récupération
étant en outre adaptés à générer lesdits premier et deuxième signaux de commande en
réaction à celles-ci.
15. Montage de reproduction selon la revendication 13 ou 14,
caractérisé en ce que les deuxièmes sections de bloc d'au moins ces blocs de signal dans un groupe de y
blocs de signal qui comprend la partie de début d'un paquet de transport comprennent
une troisième section de bloc pour mémoriser des informations de numéro de séquence
ayant rapport à un numéro de séquence de paquet de transport correspondant au paquet
de transport dont la partie de début est mémorisée dans la deuxième section de bloc
du bloc de signal;
le montage de reproduction comprenant en outre:
- des premiers moyens de récupération (60) pour récupérer les informations comprises
dans les x paquets de transport du signal d'information MPEG à partir du groupe de
y blocs de signal;
- des deuxièmes moyens de récupération (90) pour récupérer les informations de numéro
de séquence ayant rapport au numéro de séquence de paquet de transport d'une troisième
section de bloc (TB3.j) à partir d'un bloc de signal dans le groupe de y blocs de
signal.
16. Montage de reproduction selon la revendication 13, 14 ou 15,
caractérisé en ce que x et y sont des entiers de telle façon que x≥1 et y>1,
en ce que les deuxièmes sections de bloc d'au moins ces blocs de signal dans un groupe de y
blocs de signal qui comprend la partie de début d'un paquet de transport comprennent
une troisième section de bloc pour mémoriser des informations de cadencement pour
ledit paquet de transport dont la partie de début est mémorisée dans la deuxième section
de bloc du bloc de signal; le montage de reproduction comprenant en outre:
- des premiers moyens de récupération (60) pour récupérer les informations comprises
dans les x paquets de transport du signal d'information MPEG à partir du groupe de
y blocs de signal;
- des deuxièmes moyens de récupération (90) pour récupérer les informations de cadencement
à partir d'une troisième section de bloc (TB3.j) d'un bloc de signal du groupe de
y blocs de signal.
17. Montage de reproduction selon l'une quelconque des revendications précédentes 13 à
16, caractérisé en ce que y>x.
18. Procédé pour enregistrer un signal d'information dans des pistes sur un support d'enregistrement,
le procédé d'enregistrement comprenant les étapes de:
- recevoir le signal d'information;
- coder par codage de canal le signal d'information en un signal de canal,
le signal de canal comprenant des blocs de signal successifs (SB
i) d'une longueur fixe prédéterminée, chaque bloc de signal comprenant une première
section de bloc qui comprend un signal de synchronisation et une deuxième section
de bloc qui comprend un certain nombre d'octets de canal;
- écrire le signal de canal dans les pistes sur le support d'enregistrement;
caractérisé en ce que le procédé d'enregistrement est destiné à enregistrer un signal d'information sous
la forme d'un signal d'information MPEG suivant le format MPEG sur le support d'enregistrement,
le signal d'information MPEG comprenant des paquets de transport successifs d'une
longueur fixe prédéterminée;
en ce que l'étape de codage de canal comprend les sous-étapes suivantes:
- mémoriser des informations comprises dans x paquets de transport du signal d'information
MPEG dans les deuxièmes sections de bloc d'un groupe de y blocs de signal du signal
de canal, en ce que les deuxièmes sections de bloc comprennent une troisième section de bloc (TB3.j),
et
- mémoriser des informations de numéro de séquence dans ladite troisième section de
bloc, lesdites information de numéro de séquence ayant rapport à un numéro de séquence
des blocs de signal dans un groupe de y blocs de signal, et en ce que x et y sont des constantes entières pour lesquelles x≥1 et y>1.